I need help solving this word problem

Question

A store owner want to develop a new snack mix by mixing chocolate and trail mix. How many pounds of chocolate costing $19.20 per pound should be mixed with trail mix costing $2.70 per pound to create a 36 mixture worth $9.12. (round to the nearest pound)

Answer 1

I accept as 36 pounds of mixture worth $9.12. (pounds is missing above)

if we accept x as the weight of chocolate needed,

x*19.20 + (36 - x)*2.70 = 36*9.12

both sides multiplied by 100, divided by 3:

640x + 90*(36 - x) = 304*36

640x -90x = 304*36 - 90*36

550x = 214*36

x = (214*36)/550

x ~= 14